Pretreatment Duration

Ask an Expert
From: Products Finishing, David S. Peterson

Posted on:6/4/2014

How can I shorten the pretreatment time for my batch powder painting operation?

Q. I have seven tanks in the pretreatment process I use for my batch powder painting operation:
1. Degreaser
2. Water
3. De-ruster.
4. Water
5. Water
6. Zinc phosphate
7. Water

Can you please give me some advice on how I can shorten my pretreatment time?—L.M.

A. Unfortunately, what you have listed are the minimum steps that are necessary for a conversion coating. Possibly, the segment that offers any possibility to shorten the overall cycle would be if you could eliminate the de-rusting step. This would only be possible if you could control and eliminate the rust from your upstream manufacturing process. First examine the incoming parts or sheet material. Are they coming in the door rusted? If so, can you work with your suppliers to change this or have them perform the de-rusting before you receive the parts? If the rust is occurring within your manufacturing process, you can work to eliminate it through the use of in-house light oils or indoor corrosion inhibitors and reducing the amount of in-process time the parts are allowed to sit between processing steps.